Credit Suisse has already indicated that a significant portion of the settlement due to four U.S. authorities could be tax deductible in Switzerland. It assumes that roughly $2 billion of the total cannot be offset against tax, but that about “$800 million do have some tax offset,” Chief Financial Officer David Mathers said last month.

While it’s clear that elements of a settlement deemed a “penalty” can’t be deducted for tax purposes, other elements deemed “returned profits” on which the bank has already paid taxes could be deducted. Stefan Hostettler, head of policy for the Social Democratic Party in Switzerland, said that “from a legal standpoint that makes sense, but from a moral perspective it’s really irritating.”

Swiss lawmakers are expecting some clarity on the issue early next week, when the government is expected to publicly provide answers to queries tabled by members of parliament earlier this month about how much of the penalties incurred by Credit Suisse and other Swiss banks will be tax deductible. Among their concerns, the lawmakers have complained about a mish-mash of tax treatments of such penalties in various Swiss cantons and at the federal level, which complicate the picture.

Parliamentary debate should follow on Wednesday.

Mr. Hostettler said the Swiss are having some trouble grasping how a bank “can be fined, and then be able to at least partly pass on this cost to the public.”

While it’s not yet clear whether the Credit Suisse penalty will be tax deductible, U.S. banks have already made clear that settlements there could be offset against tax.

In this post in June, we told you that Bank of America’s $12-billion-plus settlement with the U.S. government over mortgage securities could come in billions of dollars lighter by shifting part of the burden to taxpayers. And when J.P. Morgan reached a deal with the government over soured mortgage securities, it too acknowledged that $7 billion of the amount would be tax deductible, although the bank didn’t say whether it would take advantage of that fact.

A Credit Suisse spokesman declined to comment on the tax treatment, and referred to previous remarks on the topic made by Mr. Mathers.